The invention relates to a method for cleaning industrial pipe systems, more precisely to a method for cleaning industrial pipe systems, preferably pipe systems used in food industry, such as meat, fish and vegetable industry, where detergent and liquid are fed into a pipe to be cleaned, and a pressure difference is created in the pipe and the detergent and liquid are brought to flow in the pipe by means of a pressure difference in order to clean the pipe.
In food industry the pipes transferring foodstuffs have to be cleaned in due time for hygienic reasons in order not to contaminate the foodstuffs transferred therein. A conventional way to clean these pipes is to feed water and detergent through the pipes. The cleaning process also includes cleaning with a disinfectant and rinsing. For example in dairy industry the cleaning agent is often fed in from one end of the pipe to be cleaned using pumps, in which case the flow is maintained until the cleaning agent flows out from the other end of the pipe. The required power of the pump has to be high, since the length of the pipe can extend up to hundreds of meters and the flow rate is, for example, 2-4 m/s. As the diameter of the pump is large, considerable amounts of cleaning agent and disinfectant have to be fed. Owing to the above, cleaning a pipe becomes very expensive.
The cleaning agent, disinfectant and rinsing agent (typically water) can be brought to flow using negative pressure as an alternative for using a pump, which is the conventional means for causing the flows. This is known from slaughtering lines. However, known systems utilizing negative pressure have not been able to provide a desired and an adequate cleaning result.
The invention also relates to an apparatus for cleaning industrial pipe systems, preferably pipe systems used in food industry, such as meat, fish and vegetable industry, comprising feeding means for feeding liquid into a pipe to be cleaned and a pressure unit for removing the liquid fed into the pipe from the pipe by means of a pressure difference.
Known apparatuses are arranged to transfer, depending on the work phase, washing agent, disinfectant or rinsing agent into the pipe along the entire length of the pipe. The water amounts used are generally large and the actual cleaning phase includes several feedings of the substances, as the inner surface of the pipe is rarely adequately cleaned during one treatment. On account of the above, known apparatuses do not enable the pipe systems to be cleaned rapidly and inexpensively.
It is an object of the invention to provide a method and an apparatus removing said drawbacks. In order to achieve this the present invention provides a method method for cleaning industrial pipe systems, having pipe walls, by mechanically treating the walls thereof, said method comprising
feeding a detergent together with liquid and granules, having a diameter, in batches only into a small part of a pipe, having a cross-section, to be cleaned, whereby one wash batch has a volume in liters, which is 0.05-0.3 times the numerical value of the cross-section in square centimeters of the pipe;
creating a negative pressure in the pipe; and
bringing the wash batch to flow in the pipe by means of the negative pressure for cleaning and mechanically treating the walls of the pipe.
Preferred embodiments of the method of the invention are disclosed below.
One of the greatest advantages of the method of the invention is that it allows industrial pipe systems having a large diameter in particular to be cleaned considerably more economically and more appropriately than previously.
The present invention provides for an apparatus for cleaning industrial pipe systems, having pipe walls, by mechanically treating the walls thereof, said apparatus comprising feeding means for feeding liquid and granules into a pipe to be cleaned and a low pressure unit for removing the liquid and granules fed into the pipe from the pipe by means of a negative pressure, said apparatus further comprising a washing center arranged by means of feeding means including a feeding pipe to feed liquid and granules into the pipe to be cleaned, the washing center comprising a container that comprises an inlet which is connected to the pipe to be cleaned for receiving material arriving from the container, removing means connected to the feeding pipe for feeding liquid through the feeding pipe to the pipe to be cleaned, the container comprising a granule space for granules, having a diameter, wherein the pipe to be cleaned includes a dosage valve for dispensing a detergent together with liquid and granules in the form of a wash batch only into a small portion of the pipe to be cleaned, the granule space comprising a feeding surface for feeding granules, said feeding surface being provided with holes having a diameter which is smaller than the diameter of the granules, the granule space being connected to the feeding pipe
The preferred embodiments of the apparatus of the invention are disclosed in the attached claims 11-13.
One of the greatest advantages of the apparatus of the invention is that it allows industrial pipe systems having a large diameter in particular to be cleaned considerably more economically and more appropriately than previously.